Question

I have the following code:

var oTable = $('#dataTable').dataTable({
 ...

I would like to declare oTable as a global but I am a bit confused. With javascript how do I do this and do I have to specify the object type when I declare it as a global?

Answer 1

Put simply, you don’t. You just declare the variable as you did, and use it wherever you need.

When you’ll want to use a global variable in a function, you can simply type its name, without declaring it first.

Example

var MyVar = $('#dataTable').dataTable(); // This is a global variable. Notice that you don't specify a type, as JavaScript is not strongly typed

function MyFunction() {
  var InternalVar = MyVar; // Here you take the value from the global variable, i.e. the datatable
}

function MyOtherFunction() {
  var MyVar = 'This is a string';

  var InternalVar = MyVar; // Here you take the value from the LOCAL variable, which you declared just above, i.e. 'This is a string'
}